Considerable effort has been directed in recent years toward obtaining substances which are useful in the treatment of hyperlipidemia, a condition associated with elevated serum-lipid levels, e.g., elevated cholesterol, phospholipid and/or triglyceride serum levels. This condition is associated with a number of diseases, one of the most serious being atherosclerosis. Medicaments used to lower cholesterol, phospholipid and triglyceride serum levels are termed hypolipidemic or antilipidemic drugs. Presently three major lipid-lowering agents are available: clofibrate, D-thyroxine, and nicotinic acid. [R. I. Levy and D. S. Fredrickson, Postgraduate Medicine, Vol. 47, pps. 130-136 (1970)]. The class of lipid-lowering compounds encompassed by the present invention may be referred to as para-[thienyl and furyl(alkyl or alkenyl)amino]benzoic acid derivatives.
U.S. Pat. No. 3,716,644 discloses and claims a method of lowering serum-lipid levels in mammals by the administration of certain (meta and para alkoxy)benzoic acids, esters, pharmaceutically acceptable salts and pharmaceutical compositions thereof. U.S. Pat. No. 3,868,416 discloses and claims certain 4-(monoalkylamino)benzoic acids, esters, pharmaceutically acceptable salts, pharmaceutical compositions thereof and a method of lowering serum-lipid levels in mammals therewith. German Pat. No. 716,668 discloses the compound p-[(3-phenylpropyl)amino]benzoic acid, however, no utility other than that in a chemical process is given for the compound. The compound p-benzylaminobenzoic acid is disclosed in Chemical Abstracts 42:5033b, 43:1345i, 45:2487e, 48:649b, 48:32846c and 49:10886g; ethyl p-benzylaminobenzoate in Chemical Abstracts 38:P2346.sup.2, 51:8720g and J. Org. Chem. 26:1437 (1961); p-[(p-methoxybenzyl)amino]benzoic acid in J. Chem. Soc. 1088 (1970); ethyl p-(.beta.-phenethylamino)benzoate and p-(.beta.-phenethylamino)benzoic acid in Chemical Abstracts 40:559.sup.3 ; and the compound p-[.beta.-(3,4-dimethoxyphenyl)ethylamino]benzoic acid in Chemical Abstracts 54:13154g. No prior art is known which discloses the para-[thienyl and furyl(alkyl or alkenyl)amino]benzoic acid derivatives of this invention and/or their utility as antilipidemic agents.